[lld] cmake cleanup

[shankarke]

Summary

cleans up unused portions in cmakefile.

[garious]

LGTM. cmake_minimum_required() can be moved into the Standalone conditional, if that is ever added back in.

[shankarke]

We dont have standalone build, but if we do we can pick it up from the repository.

[Bigcheese]

lgtm

[Eugene.Zelenko]

Fixed in r230731.

CMakeLists.txt

-# If we are not building as a part of LLVM, build lld as a standalone project,
-# using LLVM as an external library.
-
-cmake_minimum_required(VERSION 2.8)
-
 set(LLD_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
 set(LLD_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
 
 # Compute the LLD version from the LLVM version.
 string(REGEX MATCH "[0-9]+\\.[0-9]+(\\.[0-9]+)?" LLD_VERSION
   ${PACKAGE_VERSION})
 message(STATUS "LLD version: ${LLD_VERSION}")
 
if (LLD_USE_VTUNE)
   find_package(VTune)
   if (VTUNE_FOUND)
     include_directories(${VTune_INCLUDE_DIRS})
     list(APPEND LLVM_COMMON_LIBS ${VTune_LIBRARIES})
     add_definitions(-DLLD_HAS_VTUNE)
   endif()
 endif()
 
-# lld requires c++11 to build. Make sure that we have a compiler and standard
-# library combination that can do that.
-if (NOT MSVC)
-  # gcc and clang require the -std=c++0x or -std=c++11 flag.
-  if ("${CMAKE_CXX_COMPILER_ID}" MATCHES "GNU|Clang" AND
-      NOT ("${CMAKE_CXX_FLAGS}" MATCHES ".*-std=(c|gnu)\\+\\+(0x|11|1y).*"))
-    message(FATAL_ERROR
-      "lld requires c++11. Clang and gcc require -std=c++0x or -std=c++11 to "
-      "enter this mode. Please set CMAKE_CXX_FLAGS accordingly.")
-  endif()
-elseif (MSVC_VERSION LESS 1700)
-  message(FATAL_ERROR "The selected compiler does not support c++11 which is "
-          "required to build lld.")
-endif()
 
 if (MSVC)
   add_definitions(-wd4530) # Suppress 'warning C4530: C++ exception handler used, but unwind semantics are not enabled.'
 endif()
 
 include_directories(BEFORE
   ${CMAKE_CURRENT_BINARY_DIR}/include
   ${CMAKE_CURRENT_SOURCE_DIR}/include